Nursing Elites

1. What is the primary function of the respiratory system?

• A. Maintain body temperature
• B. Deliver oxygen to the bloodstream and remove carbon dioxide
• C. Produce antibodies for the immune system
• D. Break down food molecules for energy

Correct answer: B

Rationale: The primary function of the respiratory system is to deliver oxygen to the bloodstream and remove carbon dioxide. This process occurs through breathing, where oxygen is inhaled into the lungs and then transferred to the bloodstream, while carbon dioxide is removed from the bloodstream and exhaled out of the body. Maintaining body temperature (A), producing antibodies for the immune system (C), and breaking down food molecules for energy (D) are functions of other systems in the body, not the respiratory system. Therefore, the correct answer is B.

2. What is the small repeating unit in the contractile apparatus of skeletal muscle?

• A. Myofibril
• B. Actin
• C. Sarcomere
• D. Myosin

Correct answer: C

Rationale: The correct answer is 'Sarcomere.' The sarcomere is the smallest repeating unit within myofibrils and is responsible for muscle contraction in skeletal muscle. It consists of overlapping actin and myosin filaments arranged in a highly organized structure that allows for the sliding of filaments during muscle contraction. 'Myofibril' (choice A) is incorrect because it is a larger structure composed of sarcomeres. 'Actin' (choice B) and 'Myosin' (choice D) are incorrect as they are individual proteins that are components of the sarcomere, not the smallest repeating unit itself.

3. Which protein complex in the sarcomere is responsible for the thick filament?

• A. Actin
• B. Myosin
• C. Tropomyosin
• D. Troponin

Correct answer: B

Rationale: Myosin is the protein complex responsible for the thick filament in the sarcomere. It interacts with actin, another protein in the sarcomere, to generate the sliding movement that results in muscle contraction. Actin is a thin filament protein that interacts with myosin to create the sliding filament mechanism. Tropomyosin and troponin are regulatory proteins that regulate muscle contraction by controlling the interaction between actin and myosin, rather than directly being responsible for the thick filament.

4. Which type of isomerism arises due to differences in the arrangement of atoms around a double bond?

• A. Chain isomerism
• B. Functional group isomerism
• C. Cis-trans isomerism
• D. Stereoisomerism

Correct answer: C

Rationale: Cis-trans isomerism, also known as geometric isomerism, arises due to differences in the arrangement of atoms around a double bond. In cis isomers, similar groups are on the same side of the double bond, while in trans isomers, similar groups are on opposite sides of the double bond. This type of isomerism is a subset of stereoisomerism, which includes all isomers that have the same connectivity but differ in spatial arrangement. Chain isomerism involves differences in the carbon chain arrangement, functional group isomerism involves different functional groups, and stereoisomerism is a broader category that encompasses isomers with the same connectivity but different spatial arrangement.

5. Which statement is TRUE about valence electrons?

• A. They are located in the innermost electron shell.
• B. They have the highest binding energy to the nucleus.
• C. They are most likely to participate in chemical bonding.
• D. They have no influence on the element's chemical properties.

Correct answer: C

Rationale: Valence electrons are the outermost electrons in an atom's electron cloud and are crucial in forming chemical bonds with other atoms. These electrons determine the reactivity and chemical properties of an element, making option C the correct statement. Option A is incorrect as valence electrons are found in the outer shell, not the innermost shell. Option B is incorrect because valence electrons have lower binding energy compared to inner electrons. Option D is incorrect since valence electrons play a significant role in an element's chemical behavior.

Similar Questions